Facts and Types of Arch Bridges

Arch bridge is one of the most popular types of bridges, which came into use over 3000 years ago and remained in height of popularity until industrial ... HistoryofBridges BridgesHistory BridgesFacts FamousBridges ModelBridgeBuilding Home BridgesFacts ArchBridges ArchBridge-TypesofArchBridges Archbridgeisoneofthemostpopulartypesofbridges,whichcameintouseover3000yearsagoandremainedinheightofpopularityuntilindustrial revolutionandinventionofadvancedmaterialsenabledarchitecttocreateothermodernbridgedesigns.However,eventodayarchbridgesremaininuse,and withthehelpofmodernmaterials,theirarchescanbebuildonmuchlargerscales. Thebasicprincipleofarchbridgeisitscurveddesign,whichdoesnotpushloadforcesstraightdown,butinsteadtheyareconveyedalongthecurveof thearchtothesupportsoneachend.Thesesupports(calledabutments)carrytheloadofentirebridgeandareresponsibleforholdingthearchinthe precisepositionunmovingposition.Conveyingofforcesacrossthearchisdoneviacentralkeystoneonthetopofthearch.Itsweightpushesthe surroundingrocksdownandoutward,makingentirestructureveryrigidandstrong. Becauseofthisdesign,stoneandwoodarchbridgesbecomeverypopularduringtheRomanEmpire,whosearchitectsmanagedtobuildover1000stonearch bridgesinEurope,AsiaandNorthAfrica.Manyofthosebridgesremainstandingeventoday,givingusthechancetopersonallyseethewondersofthe ancientarchitecture.Romandesignswereusuallymadewithsemicirculararches,althoughseveralsegmentedarchbridgesweremadeduringtheirreign.These segmentalarchbridgeshadonecrucialdesignadvantagewhichseparatedthemfromordinarysemicircularbridges–theyenabledbridgebuilderstomorearch ofthebridgemuchhigherandlowerthemassoftheentirestructure.Thesechangesenabledbridgestomucheasiersurvivestressesoffloodsandstrong rivers.DuringthelifeofRomanEmpire,theybuiltmanywondrousbridges,lengthyaqueductswithmultiplearches,bridgeswithfloodopeningsonthe piers,andmanyothers. Ascenturieswenton,medievalarchitectsimprovedthedesignsofRomans,creatingarchbridgeswithnarrowerpiers,thinnerarchbarrels,lowerspan-rise rations,pointedarches,andincreasedspansofarches(increasingtoover70meters,mostfamouslyonthebridgeatTrezzosull'Addawhowasinusefrom 17thtotheendof18thcentury).Renaissancearchitectsinfusedintoarchbridgesnotonlysoundengineering,butalsofashionoftheirtime,creating someofthemostbeautifulandfamousbridgesofthemodernhumancivilization(suchasRialtoBridgeinVenice).Inthelast150years,iron,steeland concreteenabledcreationofmuchmoreambitiousarchbridgeswhichcannowbeseenineverycountryintheworld. TypesofArchBridges Corbelarchbridge –EventhoughCorbelarchdoesnotfunctioninthesamewayastruearchbridges(theyarenotconveyingforcesacrossthearch),theycanbecreatedto lookverysimilarlikethem.Theyaremadebylayingsuccessivelayersofmasonryorstonewitheachhavingsuccessfullylargercantilevers. Aqueductsandcanalviaducts –Tobridgelargedistances,ancientromansbuiltseriesofsupportswhichwereconnectedwithstonearches.Theseseriesofarchedstructureswerebutt notonlyinonelayerlikeordinarybridge,butwithseverallayersthatcouldreachveryimpressiveheights. Deckarchbridge –Commonarchbridgeinwhichdeckissituatedontopofthearch. Througharchbridge –ArchBridgeinwhichdeckisnotsituatedcompletelyabovethearch,butittravelsinonepartbelowitandissuspendedtoitviacablesortiebards. FamousSydneyHarbourBridgeisthebestexampleofthisdesign. Tiedarchbridge –Alsoknownasbowstringarchbridge,itincorporatesatiebetweentwooppositeendsofthearch.